The Plasma Enhanced Chemical Vapor Deposition (PECVD) process refers to a method of ionizing a gas containing atoms of a film component, into plasma by microwave or radio frequency or the like and depositing the desired film on a substrate by reaction by virtue of the characteristic of strong chemical activity of the plasma. In order to improve the manufacturing capacity of the PECVD process, the method for continuously disposing films in batch by PECVD has become a development trend.
FIG. 1(a) shows a schematic structural diagram of a conventional PECVD system for disposing films in batch. It can be seen from FIG. 1(a) that a plurality of radio frequency electrodes (each including an anode and a cathode) are arranged in an independent chamber, and each charged electrode (cathode) is connected to an independent radio frequency power supply and an impedance matching network to form an independent radio frequency discharge system. FIG. 1(b) is a schematic structural diagram of a common PECVD system for a multi-chamber film process. It can be seen from FIG. 1(b) that the PECVD system for dispose in batch includes one transfer chamber and a plurality of coating chambers, wherein the plurality of coating chambers correspond to one transfer chamber. Each coating chamber corresponds to one independent radio frequency discharge system, wherein one independent radio frequency discharge system includes a radio frequency generator, an impedance matching network and a radio frequency electrode. FIG. 2 shows a schematic structural diagram of the radio frequency system in the PECVD system.
Specifically, the operating principle that the PECVD system disposes films in batch is:
firstly, emptying the gas in each coating chamber to reach a vacuum state;
secondly, introducing a process gas into each coating chamber by a gas feed port of each coating chamber, wherein the amount of the introduced process gas is quantitatively controlled by an MFC (Mass Flow Controller); and
thirdly, when the gas is introduced into each coating chamber, because the radio frequency generator in the radio frequency discharge system of the coating chamber generates radio frequency energy and the radio frequency energy is transmitted by a matcher to an electrode plate for generating plasma, forming a stable solid film by chemical reaction and deposition of the introduced gas on the surface of a solid.
The conventional process described above are often inadequate for various applications, as explained in more details below. It is desirable to have new and improved systems and methods for operating PECVD systems.